Expansible bit.



No. 879,309. PATENTED FEB. 18, 1908.

13. PASTORE.

EXPANSIBLB BIT. APPLICATION FILED JUNE 10 1907.

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ERNEST PASTOBE, OF NEW HAVEN, CONNECTICUT.

EXPANSIBLE BIT.

To all whom it may concern:

Be it known that I, ERNnsr PASTORE, a citizen of the United States,residing at New Haven, in the county of New Haven and State ofConnecticut, have invented a new and useful Improvement in EXpansibleBits; and I do hereby declare the following, when taken in connectionwith the accompanying drawings and the letters of reference markedthereon, to be a full, clear, and exact description of the same, andwhich said drawings constitute part of this specification, andrepresent, in

Figure 1 a face view of an expansible bit constructed in accordance withmy invention. Fig. 2 a rear view of the same. Fig. 3 a sectional view onthe line 64-?) of Fig. 2. Fig. 1 a top view of the cutter, detached.Fig. 5 a rear view of the-same. Fig. 6 a view looking at the left handend of Fig. 5. 7 an end view looking at the right hand end of Fig. 5.

This invention relates to an improvement in eXpansible bits, andparticularly to those which comprise a solid head. in which anadjustable cutter is clamped in contradistinc tion. to bits in which aclamping plate is arranged on one side of the. head to clamp the cutter,the object of the invention being the cheap construction of a strong bitwhich permits the ready adjustment of the cutter, yet securely holds thesame in place and the invention consists in the construction hereinafterdescribed and particularly recited in the claims.

The head 2 of the cutter is formed integral with a shank 3 and isrovided with the usual gimlet point 4 and ffoor lip 5. Extendingtransversely through the head but slightly inclined from the horizontal,is a hole 6 into which an adjustable cutter 7 is adapted to be entered,the cutter being formed. from a steel rod corresponding in diameter tothe diameter of the hole 6 and of a length according to the diameter ofthe hole to be cut. These cutters are formed with the usual spur 8 andat what I will term the rear, with a grooved surface 9 this groovedsurface being inclined from the cutter end to the opposite end. Theopposite side of the cutter is also formed with a face 10 inclined tothe plane of the surface 9 and beveled in the opposite direction.

Entering the head from the rear is a Specification of Letters Patent.

Application filed June 10. 1907: Serial No. 378.193.

Patented Feb. 18, 1908.

threaded opening 11 which intersects the Into this hole 13 a screw 15 isinserted, the

screw having a notched head 16 and abeveled face 17 below the head whichis adapted to engage with the surface 10 of the cutter. The cutter isadjusted to project to the desired extent from the head and then thescrew 12 turned against it. This screw prevents the inward movement ofthe cutter. The screw 15 is then turned into the head so as to bring thebeveled face 17 against the inclined surface 10 of the cutter whichprevents the outward movement of the cutter and clamps the same in thehead. By forming the cutter with two opposite bevels and arranging thescrews to bear against them the cutter is securely held by these screwsagainst movement in either direction, and as the head is formed in asingle pieceit follows that a very strong bit is produced, and one inwhich the cutter may be readily adjusted or replaced and firmly held inposition.

I claim 1. The herein described expansible bit comprising a head havinga transversely arranged inclined hole, a cutter adapted to be enteredinto said hole and formed with oppositely inclined surfaces, and screwsentered into opposite sides of the head and adapted to bear against saidcutter.

2. The herein described expansible bit comprising a solid head, atransversely arranged hole extending through it, a cutter arranged insaid hole and formed at its rear with an inclined grooved surface, andwith an oppositely inclined surface opposite said grooved surface, ascrew entering the rear of the head and engaging said cutter, and ascrew entering the face of the head and having a beveled surface toengage with the cutter.

In testimony whereof, I have signed this specification in the presenceof two subscribing witnesses.

ERNEST PASTORE Witnesses:

WM. W. Sco'r'r, EDMUND J. HoUDE.

